1. Field of the Invention
The present invention relates to electrical contacts, and, more particularly, to electrical contacts comprising a cantilever beam and a spring which biases against the cantilever beam. The present invention also relates to a method of making such electrical contacts.
2. Description of the Prior Art
Although most prior art receptacle electrical contacts or terminals are formed from a single member, some female contacts do employ a composite structure in which a separate spring member is used to provide the spring force for engaging a mating male contact or pin terminal. Typical female contacts employing such a composite structure include a spring member having different spring characteristics than the material forming the remainder of the female contact. For example, U.S. Pat. No. 4,880,401 discloses a contact with a stainless steel main body including a spring tab, and a separate contact piece formed from a material suitable for connection to a printed circuit board. U.S. Pat. No. 5,246,390 discloses another multicomponent receptacle contact with an and outer spring as part of an outer sleeve that can be fabricated prom a different material or can have a different material thickness from the inner receptacle.
Another approach in which a separate member is added to a stamped and formed receptacle contact is shown in U.S. Pat. No. 4,973,271 in which a reversely folded spring is backed up by a movable support member. The movable member is located on the exterior of the receptacle contact and can include a spring that engages the base of the folded spring and is not located between the two reversely formed portions of the primary spring.
The separate spring member shown in U.S. Pat. No. 4,973,271 is inserted axially onto the mating end of the receptacle contact. Since this separate spring member is located on the exterior of the folded primary spring, this separate spring can be axially inserted below the primary spring. Another approach to inserting a separate spring member into a receptacle body in shown in U.S. Pat. No. 5,441,428 where a spring member is inserted laterally into the receptacle body while the side walls are in a partially open position. The receptacle body is then formed around the spring, in an additional manufacturing step, with the top wall enclosing the opening through which the spring was initially inserted. A laterally extending tab on the spring fits within a window on the side of the receptacle body to hold the spring in place. U.S. Pat. No. 5,226,842 discloses a similar contact with lateral tabs located at one end of the spring and at the apex of the curved leaf spring. However, these latter patents employ the separate spring as the primary spring contact instead of as a back up spring such as that disclosed in U.S. Pat. No. 4,973,271.
These prior art receptacle contacts therefore employ either a separate spring as the primary spring or employ a backup spring with a primary spring having a relatively simple configuration.